ABSTRACT
Providencia stuartii, a frequent and persistent isolate from the urinary tract of chronically catheterized elderly patients, is multiply antibiotic resistant and may cause fatal bacteremia in those patients. We studied P. stuartii strains in rats and mice to determine differences in uropathogenicity. Strains studied varied in expression of factors which contribute to pathogenicity of other bacterial species. Urinary tract responses following challenge with P. stuartii strain HO (factors expressed) were similar to responses reported for uropathogenic E. coli strains both in bacterial persistence and histologic change. In animals similarly challenged with P. stuartii strain RO (factors not expressed), responses were similar to those reported for non-uropathogenic E. coli strains. Results indicate that: a) animal model studies may be useful in differentiating P. stuartii strains based on uropathogenicity, b) P. stuartii uropathogenicity may be related to identifiable factors associated with virulence in other species, and c) the CBA mouse model appears to be the most suitable for studies of P. stuartii uropathogenicity.
Subject(s)
Proteus Infections/etiology , Proteus/pathogenicity , Providencia/pathogenicity , Urinary Catheterization/adverse effects , Urinary Tract Infections/microbiology , Animals , Female , Humans , Male , Mice , Mice, Inbred CBA , Microscopy, Electron, Scanning , Providencia/isolation & purification , Rats , Rats, Inbred Strains , Urinary Bladder/ultrastructure , VirulenceABSTRACT
Delayed chronic constrictive pericarditis developed in seven patients 51 to 268 (mean 116) months after radiotherapy. Six of the seven complained of exertional dyspnea that was initially believed to be caused by mediastinal fibrosis. All patients had raised jugular venous pressure, although in two patients this finding was not appreciated by the primary physician. There were no consistent noninvasively identifiable features to allow prediction of constrictive pericarditis other than consideration of its existence and careful examination of the cardiovascular system. All patients had constrictive pericarditis proved at cardiac catheterization. Of the five patients who underwent pericardiectomy, two had an excellent functional result, one has residual pericardial constriction and two died of unrelated causes. Recommendations for the treatment of radiation-induced pericardial disease are given.